Device and method for partially occluding blood vessels using flow-through balloon

ABSTRACT

A device and method are disclosed for partially occluding a blood vessel such that an area of hemostasis within the blood vessel is created without interrupting the blood flow through the blood vessel. The device comprises a first and second occlusive members for partially occluding a blood vessel, spaced apart from one another, wherein the occlusive members are inflatable to at least the inner diameter of the blood vessel. A tubular connector interconnects the first and second occlusive members and forms a conduit which allows the blood to flow through. When the occlusive members are inflated, an area of hemostasis is created between an outer surface of the tubular connector and an inner wall of the blood vessel while blood continues to flow through the tubular portion. A tube adapted to extend through an opening in the blood vessel to deploy the device includes multiple lumens, such as an inflation lumen to inflate the device and a suture lumen to collapse the device.

PRIORITY CLAIM

This application is a continuation-in-part of U.S. patent applicationSer. No. 09/080,823 filed on May 18, 1998, which claims the benefit ofU.S. Provisional Application Ser. No. 60/046,977 filed May 19, 1997.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a device and method for creating a region ofhemostasis along a wall of a blood vessel without interrupting the flowof blood through the blood vessel. The device may be used, for example,for creating a working area along the aorta for performing a cardiacbypass procedure or for isolating an aneurysm.

2. Background Discussion

Coronary artery diseases are often caused by atherosclerosis ornarrowing of the small arteries between the aorta and the heart muscles.There are several ways to provide blood flow around occluded segments ofarteries or veins, however, the known methods cause a large amount oftrauma to the patient. One method is to perform an "open heart surgery,"which is cracking open the chest and exposing the heart and treating thevessel directly. However, the large incision and surgically cut sternumtake a long time to heal.

Another method is to perform a bypass operation wherein a section of thesaphenous vein, or a suitable substitute, is grafted, usually betweenthe ascending aorta just above the heart and one or more of the coronaryarteries beyond the points of blockage. The bypass operation isperformed with the patient connected to a heart-lung machine and theheart is stopped. Because the heart is stopped, the heart-lung bypasscan damage blood cells. Additionally, the patient's internal bodytemperature is reduced while on a heart-lung bypass to reduce basilmetabolism and then the body temperature is increased to normal when theprocedure is over. This thermal change to a person's body can causedamage to the intestinal track as well as causing additional stress tothe patient.

If the patient is not placed on a heart-lung bypass, the aorta istypically partially clamped along its axis to create an area of bloodstasis and a small channel for blood flow. However, clamping the aortacan cause injury to the aorta and can also cause plaque formations tobreak off into the blood stream and cause vascular accidents such asstrokes and emboli.

What is needed therefore is a device and method for performing a cardiacbypass procedure without the need to clamp the aorta or place thepatient on a heart-lung bypass machine.

SUMMARY OF THE INVENTION

The present invention involves a device for partially occluding a bloodvessel such that an area of hemostasis within the blood vessel iscreated without interrupting the blood flow through the blood vessel. Inone embodiment, the device includes a flow-through balloon that isadapted to be introduced into the aorta through an incision. The balloonincludes a tubular connector having first and second partially occlusivemembers which extend radially therefrom. When the balloon is inflated, aregion of hemostasis is created along an outside wall of the tubularconnector while blood continues to flow through the tubular connector.The device thus creates an anastomosis site along a wall of the aortawithout the need to stop the patient's heart, use a cross clamp, orconnect the patient to a heart-lung machine.

In accordance with one aspect of the invention, the device comprisesfirst and second inflatable occlusive members for partially occluding ablood vessel, each occlusive member having an opening therein forpassage of blood and a tubular connector having a diameter smaller thanthat of the occlusive members extending between the openings of theocclusive members. The tubular connector is comprised of inner and outertubular portions, one of the tubular portions within the other of thetubular portions, the inner tube portion forming a lumen for blood flow,the tubular portions being attached to each other. Furthermore, theocclusive members and the tubular portions are of a single piececonstruction comprised of a single material. In addition, the devicefurther includes an inflation tube, a portion of which is disposedbetween the tubular portions.

In accordance with an additional aspect of the invention, the materialused in the balloon device is a low compliance material that stretchesby no more than about 10-20% upon inflation.

In accordance with another aspect of the invention, the device comprisesa single piece of material configured to form first and second occlusivemembers with a tubular connector therebetween, the tubular connectorbeing having a diameter less the diameter of the blood vessel and theocclusive members having a diameter approximately equal to the bloodvessel. In accordance with an additional aspect of the invention, thematerial for the balloon is expandable upon inflation to increase thediameter of the occlusive members by no more than about 20%, such thatthe occlusive members have an unexpanded diameter which is at leastabout 80% of the diameter of the vessel.

In accordance with another aspect of the invention, a surgical method isprovided for forming an incision in the aorta of a patient, inserting anocclusive device through the incision into the aorta and utilizing theocclusive device to create an area of hemostasis without interruptingblood flow through the aorta. The utilizing step includes positioningthe occlusive device at a selected location in the aorta and activatingthe occlusive device after the device is positioned by pressurizing aninflation tube connected to the occlusive device. Furthermore, thepositioning step includes using a marker on the inflation tube todetermine the position of the device within the aorta.

In accordance with another aspect of the invention, a method of treatingan aneurysm is provided for inserting an occlusive device into the bloodvessel and utilizing the occlusive device to create an area ofhemostasis along the length of the aneurysm without interrupting bloodflow through the blood vessel. The utilizing step includes positioningportions of the device on opposite sides of the aneurysm and activatingthe device.

In accordance with another aspect of the invention, a method ofmanufacturing an occlusive device is provided for providing a mandrel,applying a low compliance biocompatible material to the mandrel,removing the material from the mandrel as a single piece tubularstructure, and inserting one portion of the tubular structure insideanother portion of the tubular structure to form a tubular structurewith a double wall. Furthermore, the method of manufacturing theocclusive device further comprises inserting an inflation tube betweenthe double wall.

In accordance with another aspect of the invention, the device comprisesa tubular structure having first and second occlusive members connectedby a tubular member, the tubular structure configured to create an areaof hemostasis in a blood vessel without interrupting blood flow throughthe vessel and a length of material attached to the tubular structure ina purse string arrangement such that force on the length of materialcollapses at least a portion of the tubular structure to facilitateremoval of the structure from the blood vessel.

In accordance with another aspect of the invention, the device comprisesa first and second inflatable occlusive members for partially occludinga blood vessel that are spaced apart from each other and a tubularconnector having a diameter smaller than that of the occlusive membersextending between the occlusive members, wherein inflation of saidocclusive members creates an area of hemostasis between an outer surfaceof said tubular connector and an inner wall of the blood vessel whileblood continues to flow through said tubular connector. The devicefurther includes an indicator marker overlaid on top of the bloodvessel, which corresponds to the placement of the occlusive members andthe tubular connector such that the position of the occlusive membersand tubular connector is locatable. In accordance with an additionalaspect of the invention, the first and second occlusive members and thetubular connector are separate chambers.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of the invention will now be described withreference to the drawings of a preferred embodiment, which is intendedto illustrate and not to limit the invention, and in which:

FIG. 1 is a perspective view of a device for partially occluding bloodvessels using flow-through balloon in accordance with the invention.

FIG. 2 generally illustrates the use of the device as used in a bloodvessel, with the device shown in a deflated state.

FIG. 3 generally illustrates the use of the device as used in a bloodvessel, with the device shown in an inflated state.

FIG. 4 is a perspective view of the device, illustrating a suturethreaded through a proximal end of the balloon to facilitate collapsingthe balloon for removal.

FIGS. 5A, 5B and 5C are side views in partial cross section whichillustrate the use of a suture loop to cause the balloon to collapse forremoval.

FIG. 6 is a side view of a mandrel that may be used to form a single,continuous one-piece balloon member, with a balloon member shown thereonin cross-section.

FIG. 7 is a cross-sectional side view of a single, continuous one-piecemember formed using the mandrel of FIG. 6, with the enclosed end trimmedto create an opening.

FIG. 8 is a cut away view of the device, illustrating how the balloonmember of FIG. 6 is folded into itself to create the device inaccordance with the invention.

FIG. 9 is a cross-sectional view taken along the line 9--9 of FIG. 8.

FIG. 10 is a cross-sectional view taken along the line 10--10 of FIG. 8.

FIG. 11 illustrates the use of the device in a human aorta.

FIG. 12 illustrates the use of the device to treat an aneurysm in ablood vessel.

FIG. 13 illustrates an embodiment of the device illustrating athin-profile aspect of the invention.

FIG. 14 is a perspective view of the mandrel used to form the balloonmember.

FIG. 15 is a partially cut-away perspective view of an embodiment of thedevice, wherein internal ribs are provided within the balloon member.

FIG. 16 is a perspective view of a mandrel that may be used to form theballoon member of the type shown in FIG. 15.

FIG. 17 is a cross-sectional view taken along the line 17--17 of FIG.16.

FIG. 18 is a perspective view of another type of mandrel that may beused to form the balloon member of the type shown in FIG. 15.

FIG. 19 is a cross-sectional view taken along the line 19--19 of FIG.18.

FIGS. 20A and 20B illustrate the marker that overlay the balloon member.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In accordance with one embodiment of the present invention, a device forpartially occluding blood vessels using a flow-through balloon isdescribed herein. In order to fully specify this preferred design,various embodiment specific details are set forth. It should beunderstood, however, that these details are provided only to illustratethe preferred embodiments, and are not intended to limit the scope ofthe present invention.

With reference to FIG. 1, the present invention provides a device 9 forpartially occluding blood vessels using flow-through balloon 10. Theballoon 10 comprises a first and second occlusive members 12, 14interconnected by a tubular connector 16. In the illustrated embodiment,the occlusive members 12, 14 and the tubular connector 16 are made of asingle, continuous one-piece balloon member that provides a single,inflatable chamber, which will be discussed in more detail below.However, it will be recognized that the tubular connector 16 can be aseparate unit, which interconnects the first and second occlusivemembers 12, 14. In addition, the balloon 10 can alternatively beprovided with two or more chambers that are separately inflatable. Forexample, balloon 10 can be constructed such that the first and secondocclusive members 12, 14 and the tubular connector 16 are separate andindependent chambers. As illustrated in FIG. 1, a first seal 18 can bemade at the junction between the first occlusive member 12 and thetubular connector 16, and a second seal 18' can be made at the junctionbetween the second occlusive member 14 and the tubular connector 16. Theseals 18, 18' are formed circumferentially between the inner and outerlayers (FIG. 8) of the balloon 10, using radio frequency (RF) welding,thermal bonding, adhesive or other suitable sealing techniques.

As further illustrated in FIG. 1, a tube 20 with multiple lumens iscoupled to the balloon 10. In the illustrated embodiment in FIG. 1, twolumens are contemplated. The first lumen is an inflation lumen 17 usedto inflate the first occlusive member 12 through an opening 26 and toinflate the second occlusive member 14 through an opening 28. Theopenings 26 and 28 are formed in the inflation lumen 17 and arelongitudinally aligned with the occlusive members 12, 14 respectively.Access to the inflation lumen 17 is provided by a standard luerconnector 22, which is adapted to receive a syringe (not shown). It willbe recognized that the tube 20 can accommodate an additional inflationlumen (not shown), for example, such that each of the first occlusivemember 12, the second occlusive member 14 and the tubular connector 16through an additional opening 27 can be inflated independently of eachother. Using the syringe, the balloon 10 (including the occlusivemembers and the tubular connector 12, 14, 16) can be inflated with anappropriate fluid such as air or saline.

Alternatively, the balloon 10 can be constructed such that the occlusivemembers 12, 14 can be inflated without inflating the tubular connector16. Specifically, as illustrated in FIG. 1, a first seal 18 can be madearound the junction between the first occlusive member 12 and thetubular connector 16, and a second seal 18' can be made at the junctionbetween the second occlusive member 14 and the tubular connector 16. Theseals 18, 18' are formed between the inner and outer layers (FIG. 8) ofthe balloon 10, and prevent fluid from entering the tubular member 16.

In addition, the inflation lumen 17 may serve an additional purpose ofpreventing an over-inflation of the balloon 10. In one embodiment, theproximal end of the inflation lumen 17 is attached to an over-inflationballoon (not shown). The over-inflation balloon is attached to a luerconnector, which is attached to a luer fitting. A one-way,syringe-activated valve is built inside the luer connector. Theover-inflation balloon provides a space for sliding the distal part ofthe valve. In a preferred embodiment, the over-inflation balloon is a`Pilot` balloon made by Mallinckrodt Medical, Inc. When the physicianinserts a syringe into the luer fitting and the valve to inflate theballoon 10, a component inside the valve moves distally to allow thesyringe to inject the inflation fluid. If the physician pulls theinflation syringe out, the valve closes (the component inside movesproximally) and prevents the balloon 10 from losing its inflation. Todeflate the balloon 10, the physician inserts the syringe into the valveand withdraws the fluid.

When the balloon 10 begins to inflate, there is no resistance on theballoon 10 as it expands, and there is no back pressure in the inflationlumen 17. But when the balloon 10 comes in contact with the inner wallsof the blood vessel, the walls of the blood vessel create resistance onthe expanding balloon 10. This creates back pressure in the inflationlumen 17, and the over-inflation check balloon begins to inflate orbulge. This provides a direct signal to the physician that the inflatedballoon 10 has contacted the internal walls of the blood vessel. Thethreshold pressure level needed to inflate the over-inflation balloonmay also be produced by attempts to inflate the balloon 10 beyond itsmaximum diameter, even though the balloon 10 may not be in contact withthe vessel walls.

Alternatively, in addition to an over-inflation balloon, some otherpressure indicating device, such as a pressure meter, may be used toindicate that the desired pressure level has been reached within theballoon 10. This pressure indicating device is fluidly coupled to theballoon 10. In another embodiment, the over-inflation check balloon orother pressure indicating device is coupled to a separate lumen (notshown) which runs parallel with the inflation lumen 17 along the tube 20and extends to an opening which coincides in position with the interiorof the balloon 10.

The second lumen 19 in the illustrated embodiment of FIG. 1 is a suturelumen used to collapse the balloon 10 from the proximal portion 12. Thesuture lumen is coupled to a second luer connector 24. The suture lumenwill be discussed in more detail below.

In other embodiments, additional lumens and luer connectors may beprovided for performing additional functions. For example, in theembodiment depicted in FIG. 11, a third lumen-connector pair is providedto administer cardioplegia or other medications, and a fourth pair isprovided to monitor blood pressure. It is also contemplated that thesuture lumen and associated connector may be omitted.

As seen in FIG. 2, the balloon 10 in a deflated state is placed aroundthe tube 20 and inserted into a blood vessel 43, such as the aorta. Whenballoon 10 is inflated (FIG. 3), as discussed above, the occlusivemembers 12, 14 partially occlude blood flow along the outside of thetubular connector 16 while allowing blood to flow through inside thetubular connector 16. As seen in FIGS. 1 and 3, the occlusive members12, 14 are two partially occlusive portions that are spaced apart fromone another. In the illustrated embodiment, the occlusive portions 12,14 are shaped like a donut. It will be recognized that other partiallyocclusive shapes are also possible. When the balloon 10 is inflated, theouter diameter of the occlusive members 12, 14 equals or exceeds theinner diameter of the blood vessel 34. It will be recognized that,depending on the size of the blood vessel contemplated, the occlusivemembers 12, 14 should be appropriately sized such that upon inflation,the occlusive members 12, 14 make respective seals 36, 36¹ between theouter edges of the occlusive members 12, 14 and the inner wall 30 of theblood vessel 34. As seen in FIGS. 1 and 3, when inflated, the occlusivemembers 12, 14 extend radially outwardly from the axis of the tubularconnector 16. The diameter of the tubular connector 16 is smaller thanthe diameter of the occlusive members 12, 14 such that when theocclusive members 12, 14 come in contact with the inside wall 30 of theblood vessel 34, an area of hemostasis 32 is created between the outerwall of the tubular connector 16 and the inner wall 30 of the bloodvessel 34. The blood will continue to flow through the tubular connector16. However, the blood trapped in the area of hemostasis 32 will bestatic.

Once the region of hemostasis is created, a bypass graft (not shown) canbe attached to the blood vessel 34 (using a standard end-to-sideanastomoses procedure) between the proximal portion 12 and distalportion 14. The length of the tubular connector 16 may be varied toaccommodate different types of procedures. For example, in oneembodiment, the length of the tubular connector 16 is sufficient toprovide a working area to perform a quadruple bypass.

With reference to FIGS. 1, 4 and 5A-5C, the suture lumen 24 aspect willbe described. In the illustrated embodiment of FIG. 4, a plurality ofholes 40 are placed on a flange 42 at the proximal end of the balloon.Threaded through the holes 40 in a purse string arrangement andextending through the suture lumen 19 is a suture loop 44, a portion ofwhich is accessible to the physician via a second luer connector 24.When a manual force is applied to the suture loop 44 after the devicehas been deflated, the loop 44 will cause the flange 42 and the firstocclusive member 12 to collapse to a configuration in which the balloon10 can more easily be withdrawn through the incision. The suture loop 44or a second suture loop may optionally be coupled to the secondocclusive member 14, so that both occlusive members 12, 14 can be causedto collapse.

FIGS. 5A-5C illustrate generally how the balloon 10 collapses as a forceis applied to the suture loop 44 with the balloon in a deflated state.As best illustrated by FIG. 5C, the balloon is preferably constructedsuch that the radially-extending walls of the first occlusive member 12fold over in the distal direction.

An important feature of the device 9 is that each occlusive member 12,14 has a thin profile at its periphery, and thus contacts only a narrowsegment of the blood vessel when the balloon is inflated. By way ofbackground, existing balloon occlusion devices commonly produce alongitudinal contact distance (the longitudinal distance over which theinflated balloon contacts the inner wall of the blood vessel) whichexceeds the inner diameter of the blood vessel. In contrast, eachocclusive member of the balloon 10 described herein produces alongitudinal contact distance which is less than 50% (and preferably20-30%) of the inner diameter of the blood vessel. Because the area ofcontact is reduced, the potential damage commonly caused by such contactis also reduced. As seen in FIG. 13, the outer edges of occlusivemembers 12, 14 are preferably substantially disk-shaped. When theballoon 10 is inflated in free air, the diameter D of the balloon 10 isapproximately three to five times the peripheral length or thickness Lof each occlusive member 12, 14. In a preferred configuration, the angleA of the balloon is approximately 40 degrees.

The thin-profile occlusive members 12, 14 are preferably formed from alimited compliance material, such as polyethylene, polyurethane, otherpolymers or any other material with similar properties. The complianceof the material is preferably selected such that the balloon may stretchfrom 1% to 40% radially and from 1% to 50% longitudinally after it isinitially inflated under ambient pressure to its normal, unstretchedshape. In one embodiment, the low compliance material limits theexpansion of the balloon member to expanding 10% to 33% radially and 10%to 40% longitudinally. During such expansion, the balloon 10 does notlose its overall shape. As seen in FIG. 13, the width L of the occlusivemembers 12, 14 preferably does not expand to be more than 50% (andpreferably 20-30%) of the length of its diameter D. The use of a limitedcompliance material for this purpose reduces longitudinal stretching,and thus maintains a small peripheral surface area which contacts theinternal wall of the blood vessel. The limited compliance also preventsthe balloon 10 from blocking the tube 20 or blocking the opening of abranching blood vessel, such as the innominate artery. The limitedcompliance also reduces the likelihood of dissections and breakoffs ofthe inflatable balloon 10. The limited compliance material also reducesthe risk of the balloon bursting, which is common for silicone or latexballoons. The balloon 10 is made of a sufficiently thick material to beresistant to calcified lesions on the inner wall of the blood vessel.

With reference to FIGS. 6-8 and 14, a preferred method for manufacturingthe balloon portion of the device will be described. A mandrel 50 may beused to manufacture the balloon member 52. The mandrel is preferablycomposed of 304 (or higher) stainless steel that is electro-polishedafter machining.

During the balloon manufacturing process, the mandrel 50 isappropriately dipped in a liquid polyethylene, polyurethane or othersolution of low compliance biocompatible material a sufficient number oftimes to produce a wall thickness of approximately 0.4 mils to 0.7 mils(where 1 mil=0.001 inches). The wall thicknesses are exaggeratedthroughout the drawings to facilitate visualization of the balloon'sconstruction.

Following the dipping process, the balloon member 52 is a single,continuous one-piece member having an open end 54, a first elongatedsection 56, a second elongated section 60, and a rounded end portion 62.The first elongated section 56 is slightly smaller in diameter than thesecond elongated section 60 as a result of a corresponding difference inthe diameters of the respective mandrel sections. The balloon member 52is subsequently removed from the mandrel 50. As seen in FIG. 7, therounded end portion 62 is trimmed such that it is no longer enclosed butis open. As seen in FIG. 8, the open end 54 is then inverted inward, andthe first elongated portion 56 is pulled through the center of theballoon member 52 such that the open end 54 aligns with the rounded end62. In so doing, the first elongated section 56 forms the inner layerand the second elongated section 60 forms the outer layer of the balloon10. Because the first elongated section 56 is smaller in diameter thanthe second elongated section 60, the first elongated section fits withinthe second section. Then the multi-lumen tube 20 is inserted between thelayers of the first elongated section 56 and the second elongatedsection 60. The opening 26 and the opening 28 for inflation align withthe occlusive members 12, 14, respectively. Thereafter, the edges of theopen end 54 and the rounded end 62 are circumferentially sealed to oneanother using known sealing methods, such as RF welding, thermal bondingor adhesives.

The multi-lumen tube 20, preferably formed of a semi-rigid, translucentmaterial, such as polyethylene may be placed in between the two layers,such that when used to insert the balloon member, it allows movement toposition the device within the desired location of the blood vessel.

An optional feature of the balloon 10 will now be described withreference to FIGS. 15-20. The occlusive members 12, 14 may be providedwith pairs of internal ribs 94 (one pair visible in FIG. 15) thatinterconnect the walls of the occlusive members 12, 14. The use of suchribs 94 impedes the longitudinal expansion of the occlusive members 12,14 during inflation, and thus helps to maintain the thin profile of theocclusive members 12, 14. In one embodiment, the internal ribs limit thelongitudinal expansion of the occlusive members 12, 14 even further thanthe limited compliance material. For example, if the limited compliancematerial prevents the occlusive members 12, 14 from expandinglongitudinally by more than 50%, the internal ribs may further limitlongitudinal expansion up to only 10%. In the embodiment shown in FIG.15, the two ribs 94 that are visible overlap one another and are bondedtogether. At least three pairs of attached ribs of the type shown inFIG. 15 are preferably provided within each occlusive member 12, 14,with the pairs spaced at equal angular intervals.

FIGS. 16 and 17 illustrate one embodiment of a mandrel 50' that can beused to form a balloon 10 with the occlusive members 12, 14 of the typeshown in FIG. 15. Each face of the mandrel has eight grooves or channels96 formed therein to form eight pairs of ribs. These channels 96 becomefilled during the dipping process to form the ribs. As illustrated bythe cross-sectional view of FIG. 17 for a single channel pair, each pairof ribs 94 is formed using a pair of overlapping channels 96 that areangularly offset from one another. After the balloon 10 is removed frommandrel 50', the corresponding ribs 94 are manually glued together. Amandrel that produces non-overlapping ribs can alternatively be used, inwhich case the walls are squeezed towards one another during the gluingprocess to cause the ribs to overlap.

FIGS. 18 and 19 illustrate an alternative mandrel configuration whichcan be used to form the ribbed balloon 10. In this configuration, thechannels of the mandrel 50' of FIGS. 16 and 17 are replaced withcorresponding protrusions 98 which extend longitudinally outward fromeach face of the mandrel 50". To form a balloon 10 of the type shown inFIG. 15, the mandrel 50" is initially dipped in a liquid polyethylene,polyurethane or other solution to form a balloon 10 having ribs whichextend outward from the outer surface of the balloon. This balloon 10 isthen inverted (turned inside out) so that these ribs reside within theballoon 10. The corresponding ribs are then glued together.

It will be understood that an important use of the device 9 is for acardiac bypass procedure. As seen in FIG. 11, the balloon 10 is insertedinto the descending aorta and is then inflated to create an area ofhemostasis. In the illustrated embodiment, the balloon 10 is introducedinto the aorta through a small incision 70 in the aortic wall using adirect access surgical procedure. As would be appreciated by a personskilled in the art, the balloon 10 could alternatively be introducedinto the femoral artery via a percutaneous catheter and advanced to theaorta. Because blood can flow through the tubular connector 16 when theballoon is inflated, it is not necessary to stop the patient's heart.

An optional feature of the device is a placement of a marker, eitherattached to or separate from the tube, such that a physician mayvisualize the location of the balloon once it is inserted into the bloodvessel. FIG. 20A illustrates an embodiment wherein the marker 80 isattached to the lumen tube 20 and overlaid on the top of or alongsidethe blood vessel to indicate the longitudinal position of the balloonmember 10. The marker 80 may be made of semi-flexible material, similarto the inflation lumen 17 (FIG. 1), such that the marker 80 and theinflation tube 17 may bend and travel in tandem generally.

The marker 80 has displayed thereon an indicator zone 84 that identifiesthe safe working area (area of hemostasis) between the occlusive members12, 14. Accordingly, the physician would be able to visualize the areabetween the occlusive members 12, 14 when making any incisions, as isdesirable to avoid puncturing the balloon. The distal end of the marker80 preferably corresponds to the distal occlusive member 14, so that thephysician can ensure that the balloon is not advanced too far (e.g. intothe heart). A marker 82 may additionally or alternatively be placed onthe tube 20 for this purpose.

FIG. 20B illustrates an alternative embodiment wherein the marker 80' isnot attached to the lumen tube 20. The marker 80' also contains anindicator zone 84' and would work in a manner similar to the embodimentillustrated in FIG. 20A. In another embodiment (not shown), the markeris removably attachable to the lumen tube 20, such as through the use ofa snap-on fitting. In yet another embodiment, the marker is slidablyattached to the tube 20, and can thus be advanced distally along thetube and into position.

Another important use of the device 9 is to repair damages vessels. Asillustrated in FIG. 12, the device 9 can be used to treat an aneurysm72. To isolate the aneurysm 72, the balloon 10 is inserted (using eithera direct access or a percutaneous procedure) such that the occlusivemembers 12, 14 are positioned on opposite sides of the aneurysm, and theballoon 10 is then inflated. As will be appreciated by a person skilledin the art, the device 10 can also be used in any blood vessel wherethere is a need to isolate an area yet still allow passage of bloodthrough the blood vessel.

Although a preferred embodiment of the invention has been described indetail, other embodiments will be apparent to those skilled in the art,including embodiments that do not provide all of the features andbenefits described herein. Accordingly, the scope of the presentinvention is intended to be defined only by reference to the appendedclaims.

What is claimed is:
 1. An apparatus for use in a blood vessel,comprising:an occlusive device which comprises first and secondinflatable occlusive members for partially occluding a blood vessel,said occlusive members spaced apart from each other, and a tubularconnector having a diameter less than that of said occlusive members andextending between said occlusive members, wherein inflation of saidocclusive members creates a region of hemostasis between an outersurface of said tubular connector and an inner wall of the blood vesselwhile permitting blood to flow through said tubular connector, andwherein said occlusive members comprise respective balloons of amaterial having sufficiently low compliance to limit axial lengtheningof said balloons such that the axial length (L) of each balloon wherethe balloon contacts the vessel wall is no more than 50% of the diameterof the balloon when the balloon is inflated to create said region ofhemostasis.
 2. The apparatus of claim 1, wherein said occlusive membersand said tubular connector are of a single piece construction comprisedof a single material.
 3. The apparatus of claim 1, wherein said lowcompliance material stretches by no more than 10-20% upon inflation. 4.The apparatus of claim 3, wherein said occlusive members are providedwith pairs of internal ribs that interconnect the walls of saidocclusive members to impede the longitudinal expansion of said occlusivemembers during inflation.
 5. The apparatus of claim 1, wherein saidtubular connector is comprised of inner and outer tubular portions, theapparatus comprising an inflation tube, a portion of which is disposedbetween said tubular portions.
 6. An apparatus for use in a bloodvessel, comprising:a single piece of material configured to form firstand second occlusive members with a tubular connector therebetween, saidocclusive members allowing blood to flow through said tubular connectorwhen said occlusive members are inflated to a diameter approximatelyequal to said blood vessel, said tubular connector having a diameterless the diameter of the blood vessel when said occlusive members areinflated to said diameter approximately equal to the blood vessel,wherein inflation of said occlusive members creates a region ofhemostasis between an outer surface of said tubular connector and aninner wall of the blood vessel while blood flows through the tubularconnector.
 7. The apparatus of claim 6, wherein said material isexpandable upon inflation to increase the diameter of the occlusivemembers by no more than 20%, such that said occlusive members have anunexpanded diameter which is at least 80% of the diameter of the vessel.8. A surgical method, comprising:forming an incision in the aorta of apatient; inserting an occlusive device through the incision into theaorta; and utilizing the occlusive device to create an area ofhemostasis without interrupting blood flow through the aorta, saidutilizing comprising positioning the occlusive device at a selectedlocation in the aorta and activating the occlusive device after saiddevice is positioned by pressurizing an inflation tube connected to theocclusive device.
 9. The method of claim 8, wherein said positioningcomprises using a marker on said inflation tube to determine theposition of the device within the aorta.
 10. The method of claim 8,further comprising positioning a marker along an outer surface of theaorta to indicate a position of the occlusive device within the aorta.11. The method of claim 10, wherein the marker indicates a hemostasiszone, and the method further comprises surgically attaching a bypassgraft to the aorta within the hemostasis zone.
 12. A method of treatingan aneurysm in a blood vessel, comprising:inserting an occlusive deviceinto the blood vessel; and utilizing the occlusive device to create anarea of hemostasis along the length of the aneurysm without interruptingblood flow through the blood vessel, said utilizing comprisingpositioning portions of said device on opposite sides of said aneurysmand activating said device.
 13. A method of manufacturing an occlusivedevice, comprising:providing a mandrel; applying a low compliancebiocompatible material to the mandrel; removing the material from themandrel as a single piece tubular structure; and inserting one portionof said tubular structure inside another portion of said tubularstructure to form a tubular structure with a double wall.
 14. The methodof claim 13, comprising inserting an inflation tube between the doublewall.
 15. An apparatus, comprising:a tubular structure having first andsecond occlusive members connected by a tubular member, said tubularmember configured to create an area of hemostasis in a blood vesselwithout interrupting blood flow through the vessel; and a length ofmaterial attached to said tubular structure in a purse stringarrangement such that force on said length of material collapses atleast a portion of said tubular structure to facilitate removal of saidstructure from said blood vessel.
 16. An apparatus comprising:anocclusive device which comprises first and second inflatable occlusivemembers for partially occluding a blood vessel, said occlusive membersspaced apart from each other, and a tubular connector having a diametersmaller than that of said occlusive members extending between saidocclusive members, wherein inflation of said occlusive members createsan area of hemostasis between an outer surface of said tubular connectorand an inner wall of the blood vessel while blood continues to flowthrough said tubular connector; and an indicator marker which is adaptedto be positioned along an outside surface of the blood vessel toindicate a position of the occlusive device within the blood vessel. 17.The apparatus of claim 16, wherein the indicator marker indicatesworking area which falls between said first and second occlusivemembers.
 18. The apparatus of claim 16, further comprising a tube whichis coupled to the occlusive device, said tube adapted to be used todirectly introduce the occlusive device into a patient's aorta.
 19. Theapparatus of claim 18, wherein said indicator marker is attached to saidtube.
 20. The apparatus of claim 19, wherein the indicator marker isremovably attachable to said tube.
 21. The apparatus of claim 16,wherein said first and second occlusive members and said tubularconnector comprise separate, inflatable chambers.